Here are the top 10 updates on this big story:
The suspension of Internet services in 10 districts of Assam has been extended for another 48 hours beginning Thursday noon, Additional Chief Secretary (Home and Political) Kumar Sanjay Krishna said. While Guwahati -- Assam's largest city and epicentre of the protests -- was the first to be placed under indefinite curfew, it was later extended to Dibrugarh as protesters targeted the homes of Sarbananda Sonowal, Rameswar Teli and BJP MLA Binanda Hazarika.
Five columns of the army -- each comprising 70 personnel -- have been deployed in Assam. Two of the army columns deployed in Guwahati have carried out flag marches, news agency PTI quoted Indian Army PRO Lt Col P Khongsai as saying. Army personnel have also been deployed in Tinsukia, Dibrugarh and Jorhat districts, the news agency reported.
In a major reshuffle in the midst of the violence, the Assam government replaced Guwahati Police Commissioner Deepak Kumar with IPS officer Munna Prasad Gupta. Assam Additional Director General of Police (Law and Order) Mukesh Agarwal was also transferred, with IPS officer GP Singh being appointed in his place.
Even as violence continued unabated, Prime Minister Narendra Modi tweeted on Thursday morning that the people of Assam have nothing to worry about because "no one can take away your rights". Mr Sonowal also said in a video message that he was "resolutely committed to protect the identity, rights, heritage and culture of the Assamese people", and urged them to continue on the path of progress "while keeping alive our ancient values of peace, harmony and brotherhood".
While IndiGo announced that all its flights to and from Dibrugarh in Assam have been cancelled, SpiceJet is offering refunds and waiver of cancellation or change fees for all flights on the Guwahati-Dibrugarh route until Friday. Other airlines such as Vistara and GoAir also announced the cancellation of flights to these two cities and waived their cancellation or rescheduling fees.
Even as the Rajya Sabha cleared the Citizenship (Amendment) Bill with 125 voting for it and 99 against on Wednesday night, thousands of people descended on the streets of Assam in protest. The clashes that followed were of a magnitude unseen since the violent six-year movement by students that ended with the signing of the Assam Accord in 1985.
According to police, the headquarters of the Asom Gana Parishad -- the BJP's ally in Assam -- was attacked by people protesting against the Citizenship (Amendment) Bill in Guwahati's Ambari area. Two railway stations in Dibrugarh's Chabua and Tinsukia were also set on fire, a Northeast Frontier Railway spokesperson said. Chabua is the hometown of Mr Sonowal.
In Tripura, three columns of the Assam Rifles, a paramilitary force commanded by Army officials, were pressed into service on Wednesday, the Army said. A defence spokesman had earlier said in a statement that two columns of the army were deployed in Tripura.
Internet services in Tripura have already been suspended for 48 hours, starting 2 pm on Tuesday. The opposition Congress has also called for a shutdown in the state to protest the bill, which makes it easier for non-Muslim migrants to gain Indian citizenship. While opposition parties have accused the bill of bring discriminatory against Muslims, protesters in the Northeast claim that it will end up robbing the region of its identity.
The Citizenship (Amendment) Bill was cleared by the Lok Sabha two days earlier, with 334 MPs supporting it in a house where the government enjoys brute majority. Although the ruling BJP does not have a majority in the Rajya Sabha, it managed to get the numbers needed to pass the bill with the help of regional parties such as the Biju Janata Dal and Telugu Desam Party.
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